Marine Governors. 655 If, on the contrary, a heavy load is put on the engine, the governor revolving at a low height gives the valve the utmost travel, securing a late cut-off. The Shaft governor provides automatic cut-off by a very simple and compact arrangement, especially adaptable to small high-speed engines. The gear of the Westinghouse engine is shewn at (£) Fig. 652, the object being to directly vary the eccentric throw. A A is a disc fixed to the crank shaft, having pins B B for carrying centrifugal weights E E, and pin H for supporting the eccentric H j. The latter may rock to the right or left on pin H by a limited amount, to be determined by the position of weights EE, their deviation causing an alteration in the eccentric throw. The weights are connected by the link c D, so that their movements shall be simultaneous, and are attached to the eccentric by link F G. If the engines then revolve at a high speed, the weights E E fly outward and pull the eccentric sheave to the left, decreasing throw and producing early cut-off; if the speed decreases, the strong springs K K bring the weights towards the centre and increase the throw. (See p. 1145.) Marine Governors have always been difficult to devise, and, although no perfect governor exists, the arrangement at (a) Fig. 652 is one of the best, acting as it does on a direct principle. The fluctuations in speed of a marine engine are caused by the propeller either partly or entirely leaving the water rather suddenly, thus decreasing the load. The consequent increase of speed or £ racing' cannot be entirely obviated, but may be considerably modified by the use of Dunlop's governor, c is a large pipe communicating with the water near the propeller, and D an air chamber which can be shut off from c by the screw-down valve A, worked by hand-wheel B. F is a pipe containing only air, the entrance of water being prevented by the baffle-plate E. H is a diaphragm in communication with F, and L K. a rod which partakes of the movement of H, transmitting it to the piston slidb valve M, for admitting to or exhausting from cylinder p. The cock L admits steam to M, and the piston rod Q R is connected to the lever R s, which has its fulcrum at w. Finally, s T is a rod for actuating a throttle valve in the high-pressure steam pipe of the engine.